A Radio-Frequency (RF) transceiver of a wireless communication device may include two physically separate baseband branches to generate high-frequency in-phase (I) and quadrature (Q) signals, e.g., at phases of 0° and 90°. This configuration results in an inherent I/Q imbalance.
The I/Q imbalance should be calibrated, in order to achieve a required level of accuracy in terms of phase and/or gain, e.g., of a Transmit (Tx) path and a Receiver (Rx) path of the transceiver.
Transmitter imbalance calibration may be performed by generating a Single Side Band (SSB) signal in a digital domain of the transceiver, using an envelope detector to detect the presence of I/Q imbalance, and applying an iterative loop to minimize the detected imbalance.
Receiver imbalance calibration may be preformed by using an external test-equipment (TE) source to inject an SSB signal into the receiver path, and performing measurements in the digital domain to calculate the required correction coefficients for the I/Q imbalance.
Alternatively, the receiver imbalance calibration may include calibrating the transmitter, and using the transmitter for generating a reference SSB signal to be injected into the receiver.